package com.taxshare.purchaser.util;

import java.awt.image.BufferedImage;
import java.io.*;
import java.util.ArrayList;
import java.util.List;
import javax.imageio.ImageIO;

import com.taxshare.tools.util.FileToBase64;
import org.apache.pdfbox.pdmodel.PDDocument;
import org.apache.pdfbox.rendering.ImageType;
import org.apache.pdfbox.rendering.PDFRenderer;

/**
 * @ClassName: pdf转jpg
 * @Description:
 * @author: Hai
 * @date: 2021/5/24 9:37
 */
public class PdfchangeOneImg {

    /**
     * pdf文件流转 base64二进制图片文件
     *
     * @param is 文件流
     * @return base64二进制图片文件
     * @throws Exception
     */
    public static String useStream(InputStream is) throws Exception {
        String imageStr = null;
        try {
            PDDocument pdf = PDDocument.load(is);
            int actSize = pdf.getNumberOfPages();
            List<BufferedImage> piclist = new ArrayList<BufferedImage>();
            for (int i = 0; i < actSize; i++) {
                BufferedImage image = new PDFRenderer(pdf).renderImageWithDPI(i, 100,
                        ImageType.RGB);
                piclist.add(image);
            }
            imageStr = yPic(piclist);
            is.close();
        } catch (IOException e) {
            e.printStackTrace();
        }
       return imageStr;
    }


    /**
     * 将宽度相同的图片，竖向追加在一起 ##注意：宽度必须相同
     *
     * @param piclist 文件流数组
     */
    public static String yPic(List<BufferedImage> piclist) {// 纵向处理图片
        if (piclist == null || piclist.size() <= 0) {
            System.out.println("图片数组为空!");
            return null;
        }
        String imageStr = null;
        try {
            int height = 0, // 总高度
                    width = 0, // 总宽度
                    _height = 0, // 临时的高度 , 或保存偏移高度
                    __height = 0, // 临时的高度，主要保存每个高度
                    picNum = piclist.size();// 图片的数量
            int[] heightArray = new int[picNum]; // 保存每个文件的高度
            BufferedImage buffer = null; // 保存图片流
            List<int[]> imgRGB = new ArrayList<int[]>(); // 保存所有的图片的RGB
            int[] _imgRGB; // 保存一张图片中的RGB数据
            for (int i = 0; i < picNum; i++) {
                buffer = piclist.get(i);
                heightArray[i] = _height = buffer.getHeight();// 图片高度
                if (i == 0) {
                    width = buffer.getWidth();// 图片宽度
                }
                height += _height; // 获取总高度
                _imgRGB = new int[width * _height];// 从图片中读取RGB
                _imgRGB = buffer.getRGB(0, 0, width, _height, _imgRGB, 0, width);
                imgRGB.add(_imgRGB);
            }
            _height = 0; // 设置偏移高度为0
            // 生成新图片
            BufferedImage imageResult = new BufferedImage(width, height,
                    BufferedImage.TYPE_INT_RGB);
            for (int i = 0; i < picNum; i++) {
                __height = heightArray[i];
                if (i != 0){
                    _height += __height; // 计算偏移高度
                }
                imageResult.setRGB(0, _height, width, __height, imgRGB.get(i), 0, width); // 写入流中
            }
            InputStream  fileInputStream = bufferedImageToInputStream(imageResult);
            imageStr = "data:image/jpg;base64," + FileToBase64.getBase64FromInputStream(fileInputStream);
        } catch (Exception e) {
            e.printStackTrace();
        }
        return imageStr;
    }

    /**
     * BufferedImag转InputStream
     *
     * @param image
     * @return
     */
    public static InputStream bufferedImageToInputStream(BufferedImage image){
        ByteArrayOutputStream os = new ByteArrayOutputStream();
        try {
            ImageIO.write(image, "jpg", os);
            InputStream input = new ByteArrayInputStream(os.toByteArray());
            return input;
        } catch (IOException e) {
            e.printStackTrace();
        }
        return null;
    }
}
